A simple magnetic pulse to the head could improve memory for Alzheimer’s disease sufferers or stroke patients, a study has found.

Scientists at Northwestern University in the US, discovered that stimulating parts of the brain improved memory by more than 20 per cent.

And the effects appear to last for several days after the treatment.

"We show for the first time that you can specifically change memory functions of the brain in adults without surgery or drugs, “said senior author Dr Joel Voss, assistant professor of medical social sciences at Northwestern University Feinberg School of Medicine

"This non-invasive stimulation improves the ability to learn new things. It has tremendous potential for treating memory disorders."

Researchers used a technique called Transcranial Magnetic Stimulation which uses a magnetic pulse to trigger electrical charges in the brain cells, forcing them to become more active.

Dr Voss said it was like giving the brain regions a more talented conductor so they play in closer synchrony.

They tested the memory of 16 volunteers between 21 and 40 who were all in good health. They then used a MRI machine to work out exactly which part of the brain was storing memories.

Memories are stored in the hippocampus, an area in the middle of the brain roughly at eye level. But the exact area can differ by up to a centimetre between individuals. Although the hippocampus is too deep for magnetic fields to penetrate, the team found an area directly above it which has direct contact.

Once they knew the exact area to target, the volunteers received brain stimulation 20 minutes a day for five consecutive days.

The researchers discovered that the volunteers performed around 20 per cent better on memory tests compared with an untreated control group, who showed no improvement during the period.

"They remembered more face-word pairings after the stimulation than before, which means their learning ability improved," Dr Voss said.

"That didn't happen for the placebo condition or in another control experiment with additional subjects.

. "The more certain brain regions worked together because of the stimulation, the more people were able to learn face-word pairings, " Voss said.

They are hopeful the technique could be used to help the early symptoms of Alzheimer’s disease; depression, schizophrenia and other mental health problems.

The current study was with people who had normal memory, who researchers did not expect to see a larger improvement because their brains are already working effectively.

"But for a person with brain damage or a memory disorder, those networks are disrupted so even a small change could translate into gains in their function," Voss added.

In an upcoming trial, he will study the electrical stimulation's effect on people with early-stage memory loss.

Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:

“The results of this study shows some potential in the use of a non-invasive technique which may help to improve memory. This was a very small trial with only 16 people and did not look specifically at people with Alzheimer’s disease or other forms of dementia. Much more large-scale, long-term research is needed to determine whether this technique would be beneficial to people with dementia.

“There is currently no effective treatment or cure for Alzheimer’s or dementia. We urgently need an effective treatment that could stop the

The study was published in the journal Science.

In a separate study, the University of Huddersfield has discovered that a key ingredient found in pomegranates could help slow the onset of Alzheimer’s disease.

Dr Olumayokun Olajide found that punicalagin can prevent inflammation in brain cells.

This inflammation leads to the destruction of more and more brain cells, making the condition of Alzheimer's sufferers progressively worse.

The team is hopeful that a drug derived from punicalagin that could treat neuro-inflammation and slow the disease.